Automatic sheet metal reforming hammer



Oct. 20, 1953 J. GENDRON 2,655,825

AUTOMATIC SHEET METAL REFORMING HAMMER Filed NOV. 29, 1951 JosephGendron I N V EN TOR.

Patented Oct. 20, 1953 UNITED STATES PATENT OFFICE AUTOMATIC SHEET METALREFORMING HAMMER 1 Claim. 1

The present invention relates to new and useful improvements in toolsfor removing dents from sheet metal and more particularly to a poweroperated picking hammer for use with automobile body and fender repairwork.

An important object of the invention is to provide a tool of thischaracter adapted for use in places normally inaccessible to handoperated tools and wherein the hammer is rapidly actuated to quicklycomplete the job.

Another object is to provide a device of this character of simple andpractical construction, which is eflicient and reliable in operation,relatively inexpensive to manufacture, and otherwise Well adapted forthe purposes for which the same is intended.

Other objects and advantages reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming part hereof, wherein likenumerals refer to like parts throughout, and in which:

Figure 1 is a side elevational view;

Figure 2 is a longitudinal sectional view; and,

Figure 3 is an enlarged transverse sectional view taken on a line 3-3 ofFigure 2.

Referring now to the drawing in detail, wherein for the purpose ofillustration I have disclosed a preferred embodiment of my invention,the numeral 5 designates a barrel in the center of which a hollowplunger 6 is slidable. A rod 1 is welded or otherwise suitably fixed atits central portion to plunger 6 with front and rear guide plugs 8 and 9pressed in or otherwise suitably fixed in the front and rear endsrespectively of the barrel. Front and rear opposing coil springs l and Il are positioned in the barrel, front spring I0 being held between theplunger 6 and front fixed plug 8 and rear spring ll being held betweenplunger 6 and rear fixed plug 9. The rod 1 extends through rear plug 9to project rearwardly beyond the rear end of the barrel into the frontend of a pulsating type pneumatic tool 12 of a conventional type foractuation by the reciprocating piston 93 of the tool. The tool I2 isattached to the rear end of barrel 5.

A head I 4 is constructed of a pair of spaced apart side plates l and I6with a rear collar ii welded between th rear edges of the plates and isthreaded on the front end of the barrel. A front collar 18 is weldedbetween the front edges of the plates substantially at right angles torear collar ll.

A hollow guide plug I 9 is threaded in the lower end of front collar 18and in which the front end of a reciprocable pick hammer 20 is slidable.The

hammer is held in a retracted position by a coil spring 2| held betweenplug l9 and a flange 22 adjacent the rear end of the hammer. The rearend 23 of the hammer is received in a recess 24 at the front end of asubstantially bell crank arm 25 which is pivoted adjacent its centralportion on a transverse pin 26 supported by the plates 15 and I6 andwith the rear end 21 of the bell crank arm positioned in the path offorward movement of the front end of rod 1.

In the operation of the device rod l is pushed forwardly by the pistonI3 of the pneumatic tool causing the front end of the rod to strike therear end of bell crank arm 25 to rock the arm and project hammer 20.During forward movement of rod 1 the plunger 6 carried by the rodcompresses front spring ID and upon completion of the forward stroke ofthe rod spring I!) returns the rod rearwardly and spring 2! retractshammer 20 and such action of both springs I 0 and 2| is opposed by rearspring II which is compressed by the rearward movement of plunger 6 andtends to check the return movement of the rod and also tends to hold therod engaged with arm 25 and results in a rapid reciprocativ movement ofthe rod.

Accordingly, by placing the front end of the hammer against a dent in afender or other sheet metal work the dent will be rapidly hammered tosmooth the same.

Although the barrel 5 is shown attached to a pneumatically operated toolit will be apparent that the same may also b used with electrically ormechanically operated tools as well.

In View of the foregoing description taken in conjunction with theaccompanying drawing it is believed that a clear understanding of thedevice will be quite apparent to those skilled in this art. A moredetailed description is accordingly deemed unnecessary.

It is to be understood, however, that even though there is herein shownand described a preferred embodiment of the invention, the same issusceptible to certain changes fully comprehended by the spirit of theinvention as herein described and the scope of the appended claim.

Having thus described the invention, what is claimed as new is:

A sheet metal picking hammer comprising a barrel, a reciprocable rod inthe barrel, a head at the front end of the barrel, a guide in the head,an elongated hammer slidably mounted in the guide and positionedsubstantially at right angles to the rod, spring means retracting thehammer, a substantially bell-crank arm pivoted to the head and havingone end engaging the rear end of the hammer and having its other end inthe path of movement of the rod, front and rear springs in the barrel,an abutment at the front end of the barrel for the front spring, anabutment at the rear end of the barrel for the rear spring, means fixedto the rod for movement therewith and separating said front and rearsprings to compress the front spring upon a forward movement of the rodamif to compress the rear spring upon a rearward movement of the rod,said front and rear springs opposing each other to tend to reciprocatethe rod, and said rear spring maintaining the forwardrend-efl the rocL-in engagement with said bell-crank arm, and means connected to the rearend of the rod to actuate the same.

JOSEPH GENDRON.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,151,361 Hi1nter Aug. 24, 1915 2,004,459 Boehnke June 11,1935 2,175,946 Margolis Oct. 10, 1939 2,319,478 Rybak May 18, 1943

